The people of the Omega Empire live under Emperor Duke's crushing rule — paying impossible taxes under the threat of violence or death. The resistance movement Psi, headed by renegade leader Edgar, operates openly as jacks-of-all-trades helping citizens while secretly conducting targeted assassinations of Imperial officials and criminals. One of Psi's members is Hazuki — a dark-haired woman who looks nothing like an assassin, armed with her beloved sword Oborozuki, ready to face the empire again.